Poor eating habits, sedentary behavior, and deficient sleep quality are problematic for many college students. Surrounded by numerous unhealthy food choices and physical activity barriers, students are vulnerable to overweight and chronic diseases such as diabetes, heart disease, and cancer. Today's college students are more technologically connected than previous generations positioning mobile devices as an ideal method for reaching this population with healthy lifestyle information. In a Phase I SBIR, our team developed Healthy Detours, an innovative mobile phone application (app) designed to assist college students make healthier choices about food and physical activity on and around their college campus. Specifically, we (a) developed a comprehensive database to provide user-specific information through the use of location-based services (LBS) focused on healthy lifestyle choices; (b) conducted an online survey with a national sample of undergraduates which examined eating and physical activity preferences, interest in smartphone technology to monitor healthy lifestyle choices, and use of check-ins for health information; (c) conducted focus groups which demonstrated the prototype app's ability to provide the user with rudimentary aspects of the LBS database to facilitate real- time decision making for healthier choices; (d) conducted lab and field usability testing of the app for its accuracy in identifying user location and functionality; and (e) developed a specifications document to outline the Phase II development plan. The results of the Phase I activities provided strong support for this Phase II SBIR application in which we propose to develop an interactive, mobile app that is guided by the Theory of Planned Behavior (TPB) and Social Cognitive Theory (SCT). The proposed Phase II project will produce a fully functional LBS smartphone app that will provide (1) immediate and relevant feedback at the point of decision- making to reinforce healthy lifestyle behaviors, (2) person- and location-specific tailored data, acquired through activity tracking, to provide users with necessary information to improve future decision-making, and (3) multiple health-tracking features that will aid in self-monitoring. Healthy Detours will be evaluated in a randomized controlled trial (n=300) with students at a large 4-year university. Primary outcomes include changes in dietary intake, physical activity behavior, sleep quality, and quality of life. Overall, the proposed project has the potential to significantly impact colleg students' health and quality of life by providing them with real-time healthy choices. Healthy Detours is one of the first comprehensive wellness apps offered to college students, and provides an opportunity via the SBIR funding mechanism to reach a large number of students as evidenced by our commercialization plan.